Impedance matching in volume control or speaker selector?

[Shezzy in SJ]

I posted this over at avsforum, but haven't received an answer yet, so I found you guys and thought I'd ask it here.

We are remodeling and putting in ceiling speakers with volume controls. Five pair. I have heard that using a speaker selector with impedance matching is actually not as "efficient" as using the volume controls with impedance matching. But then, how do I home run and combine five pairs of speakers to the receiver if I am not needing/usiing a speaker selector? Is there some sort of junction box to gang all the speaker wires together, instead of twisting them all together in a bundle and jamming it into the back of the receiver?

THANKS,
Sherry.

 

[jaxvon]

If you don't get a reply soon, PM BMXTRIX. He's an experienced custom installer.

 

[JohnA]

What you will do is take the output to a speaker distribution block/hub and then to each volume control (Impedance matching).

Buffalo electronics has a hub VC-J8 (4" x 4" plastic junction box style)

http://www.buffaloelectronics.com/p-vcj8.htm

Wired home has a distribution hub

http://wiredhome.com/audio.html

Hope that helps!

 

[AVRat]

crutchfield.com carries the Niles VCS HUB8 for $55. http://www.crutchfield.com/S-pFm3jS3ugFX/cgi-bin/ProdGroup.asp?g=15240

In case you don't know, FYI, using the IM Volume controls for 5 speakers will give you 1/4 of your available power to each speaker. 120W amp = 30W/speaker

 

[j_garcia]

I need to know this too. I'm not doing separate volume control, though I am installing 3 sets of speakers into 3 rooms. I was looking at the Niles SS-4 to do the switching. With the hub8, would I NEED IM volume controls or would volume control via the receiver be sufficient?

 

[JohnA]

I need to know this too. I'm not doing separate volume control, though I am installing 3 sets of speakers into 3 rooms. I was looking at the Niles SS-4 to do the switching. With the hub8, would I NEED IM volume controls or would volume control via the receiver be sufficient?

The Niles would work fine for the "switching" however there is no independent control for each room. You would be better off using a speaker selector with built-in volume controls or place volume controls in each location. The problem with using the volume control from your receiver is that it is universal for all speaker location, so if you turn it down, it goes down in all locations (which might not be what you want) The price for the Niles is high, you can find others of the same quality for less, see the links I posted above.

 

[j_garcia]

I don't want to hijack this thread, so I'll start another one. Thx.

 

[Shezzy in SJ]

Hey, thanks for the replies. You've reminded me that I had heard of the Buffalo hub, but I had forgotten the name of it. I will look at that, as well as wiredhome's.

But, with AVRat's comment, I am now so confused. If with the five impedance matching volume controls I am LOSING power, than that is exactly opposite from what I thought I heard from a friend of a friend. He had just put in something similar, but I'm getting his info. third hand. He told my friend, who told me, that the impedance matching in the speaker selector somehow "chokes" off "juice" from what is available to go to each volume control. But AVRat is saying that, in essence, and I can see how it's logical, that with impedance matching happening AFTER the wire length hubbing from the home run, then each volume control is getting less - except that he is talking watts/power and I thought IM referred to ohms/resistance.

So DOES the impedance matching in a speaker selector box have the "choked" effect that the friend-of-the-friend said there was? Or is this negligable and splitting hairs, or wires?

Please know, 48 hours ago, this was all Greek-to-a-Chinaman (no offense intended, please) to me. I'm treading water as fast as I can to keep the brain cells from submerging below the level of comprehension. So don't feel bad if you give me the AV for Dummies treatment.

If it helps, my receiver is a 20-year old Pioneer SX-780, with A and B switches, with "continuous power output of 45 watts per channel, min., at 8 ohms from 20 Hertz to 20,000 Hertz with no more than 0.05% total harmonic distortion", per the manual. Of the five pairs of speakers, two pair will be on simultaneously very often, three pair on together slightly less often, four pair only very occasionally, and five pair all at once, almost never.

THANKS,
Sherry.

 

[j_garcia]

I know that the Niles switches state that you should use an amp/receiver that is capable of 4 Ohms. I picked up a used amp that is 2 Ohm stable so I don't think I'll have a problem, though I might be concerned about using an older, lower power receiver in your application, depending on the speakers and how much current they are going to need.

 

[JohnA]

Shezzy in SJ: Most speaker selectors/distribution hubs do just that, distribute the audio source. So if a distribution hub is rated at 100 watts per channel then that is the "total" amount of watts that it can take. Let's say that you have 2 different sets of speakers hooked up...that means that you have 100 watts per ch. to split between the two, which could be distributed differently such as 30/70 or you may not (and most likely you won't) use all 100 watts. So if you have 4 sets of speakers you could send each set 25 watts per ch which should be fine for whole house audio. Does that help?

 

[Shezzy in SJ]

Maybe I'm in over my head and just don't know it because I won't put my feet down - so I'll just keep kicking away.

The speakers I'm looking at are 135 watts or 150 watts (two different types). Is that overkill (watt wise) if my receiver handles "45 watts per channel," and one channel will be used for the speaker selector, splitting the 45 watts into four paths?

Does this have anything to do with what we're talking about? From the manual: "The independent left and right channel power meters enable the strength of the output signal to be read out directly, thanks to their logarithmic compression circuitry, from 0.01W up to 100W without any switches having to be thrown."

I really appreciate you guys taking the time with me on this. I've been to four local stereo and home theater stores (from high-end to main stream to tech-geek) and have been utterly underwhelmed by the customer service I've received. My husband, who has so much on his plate right now and can't fit this part of our remodel on his learning curve, has actually witnessed the implausible vague answers I've been receiving to some of these same questions. I'm in the "silicon valley" which is supposedly gilded with techno-geeks, and I can't tell you the number of times I've heard "I dunnoboutthat", or I've actually had to correct them about stuff that I learned on this forum. I know in-ceiling speakers are boring in this age of plasma and 7.1s, but my purchase price has the potential to equal that of a really nice TV. So I don't get it.

Sorry for the spew.

Just want inceiling speakers with independant volume controls, with impedance matching in there somewhere, with or without a speaker selector as recommended or not......so I can go on to the next task which is hanging drywall and mud/tape/finish the walls.....as soon as I can get a plumber to show up.

THANKS
Sherry.

 

[j_garcia]

I'm in your area, and I sort of do this stuff as a side business. I have lots of contacts with stores in the area, and I can at least try to point you in the right direction for some of these things. I only deal with shops that have excellent customer service. I can also get discounts with select stores. E-mail me direct if you like.

Don't worry too much about the wattage rating on the speakers, as that is also a maximum rating, not a requirement. As John A touched on, you'll probably be using around 25w or less for typical playback at average volume levels.

 

[AVRat]

But are you having fun?

It is rather exasperating when you know more than those you are looking to for help. I think you have to look at your options broken out to determine which route you wish to take. Then decide which products you want to use and find locations to purchase them.

1) Speaker selector w/ Volume Control box
2) Speaker selector box (provides impedance matching) to independent Volume Controls at location
3) Independent Volume Controls w/impedance matching at location through a speaker hub

I think you're starting to see light at the end of THIS tunnel.

 

[Shezzy in SJ]

Thanks you guys.

AVRat, I'll be seeing the light as long as I keep banging my head up against the tunnel. The "problem" is that I can't figure out why one would choose #2 over #3, or visa versa. (Know I'm not going for #1 option.) I am interested in the "whys," yet haven't some across clear reasons for either set up, and so I'm stumped. If there's no real difference between IM/SS w/ independent VCs in each room or hub w/ IM/VCs in each room, do I flip a coin?

J Garcia, thanks for the invite to email you, yet your contact link on your profile seems to be blocked, or something.

Did I throw into the mix yet that I have a powered sub that will be in one of the rooms with a pair of standing speakers and they will be on a VC, as well? Have heard that I can't put a powered sub on a VC. What do I do?

THANKS,
Sherry.

 

[j_garcia]

J Garcia, thanks for the invite to email you, yet your contact link on your profile seems to be blocked, or something.

Weird. E-mail. At least we can talk about what shops you've been talking to already, and see if I know any other places that might be of some help.

 

[AVRat]

I think it boils down to convenience. How much running around the house do you want to do to turn volume up or down? You could probably flip a coin and be happy.

Regarding sub/speakers issue, oh no something else! LOL. I think it's ok but you will have to go through the sub's high level/speaker level ins and outs to accomplish it.

 

[9f9c7z]

Don’t know where it fits into what you are after, but maybe thinking ‘industrial’ will work. Every big building with a distributed music and/or PA system has the same issues you are talking about, and they don’t use speakers with volume controls.

Rane makes rack mount 100watt per channel amps and in-room volume controls that look like a light switch with a dial on it, fits in a std e-box. Your choice of speakers wouldn’t be the issue because all of the control is local to each room/channel, but the power for the system is centrally located. Nice looking stuff. You can see it on this web page:

http://www.rane.com/ma4.html

Edit: btw, there are some RaneNotes on the Rane website with excellent info on issues regarding distributed sound, what works and why, what doesn’t and why, etc… It’ll take awhile to read all the stuff, everything from a simple office music system to design considerations for wiring an installed sound system in a sports arena.